US scientists have developed a 3D printer that's capable of building complex human organs and tissues.

Although 3D printing technology is widely used in science, technology and aerospace engineering, its use in medicine has so far proved fairly limited.

Dr Chris Smith of The Naked Scientists told This Way Up's Simon Morton that's because the human body is composed of many different types of living cells, and printing mixtures of cells in a way that keeps them alive and also in the right position to form a functional tissue has been impossible.

Now a team led by Wake Forest School of Medicine researcher Anthony Atala has unveiled a 3D bioprinter which can produce human scale complex tissues made up of multiple cell types.

Writing in the journal Nature Biotechnology the research raises the tantalising prospect of printing entire human organs. "With further development, this technology may produce clinically useful tissues and organs that incorporate multiple cell types at precise locations to recapitulate native structure and function," the researchers said.